Unique Statistics:

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

Abstract

The aim of this study was to investigate the occurrence of bacterial cross-contamination between the nasal cavity and leg ulcers. Sixteen patients were included in the study. Staphylococcus aureus was isolated from the leg ulcer of 13 patients and 6 of these patients also harboured S. aureus in the nasal cavity. Klebsiella oxytoca was found in the ulcer and the nasal cavity of one patient. PFGE analysis revealed that patients harbouring S. aureus both in the nasal cavity and the leg ulcer had the same bacterial type at both sites. None of the S. aureus isolates were methicillin resistant.

INTRODUCTION

Wound contaminants are likely to originate from three main sources: 1) the environment e.g. exogenous microorganisms in the air or those introduced by traumatic injury, 2) the surrounding skin and 3) endogenous sources involving mucous membranes [1]. Staphylococcus aureus is an important cause of human infections ranging from mild to life-threatening and is frequently isolated from chronic leg ulcers [2]. S. aureus inhabit multiple sites of the skin and mucosal surfaces of carriers; however, the primary reservoir of staphylococci is believed to be the anterior nares. S. aureus nasal carriage is a major risk factor for both community-acquired and nosocomial infections and there seems to be an epidemiological link between nasal carriage and infections with S. aureus [3-7].

The purpose of this study was to investigate whether the bacterial species found in chronic leg ulcers were also present in the nasal cavity of the same patient.

Sixteen patients admitted to the Copenhagen Wound Healing Center, Bispebjerg Hospital, Denmark were included in the study. The patients suffered from persistent venous leg ulcers and all patients had previously been part of the SUE project [2]. A swab was taken from the ulcer and the nasal cavity of the patients. The swab was immediately placed in SSI Stuart transport medium (SSI 28733, Denmark) and processed the same day as collected.

Media and agar plates were purchased from Statens Serum Institut (SSI), Denmark. Swabs were cultured as described before [2]. All representative colonies were isolated and identified by standard microbiological methods, and where appropriate, commercial identification kits were used to assist identification (VITEK GNI+, ID 32 Kits, BioMerieux, France).

All S. aureus strains found in this study and the SUE study [2] were tested. A bacterial suspension yielding semi-confluent growth was spread on a susceptibility 5 % blood agar plate (SSI 723, Denmark) with the following NeoSensitabs (Rosco, Taastrup, Denmark): cefoxitin, penicillin, gentamicin, mecillinam, erythromycin, polymyxin, fucidin, vancomycin and rifampicin. Plates were incubated overnight at 37ºC, and inhibition zones were measured. Susceptibility interpretations were based on the manufacturer’s recommendations.

All S. aureus strains were characterized by pulse-field gel electrophoresis (PFGE) after digestion with SmaI as described by Skov et al., 2005 [8].

S. aureus was found in 13 of the 16 ulcers. Six out of the 13 patients also harboured S. aureus in the nasal cavity. Klebsiella oxytoca was found in the ulcer and the nose of one patient, but besides this no other bacterial species isolated from the ulcers were found to be present in the nasal cavity. To the best of our knowledge, this is the first study on the possible transmission of S. aureus from the nasal cavity to chronic leg ulcers.

Fig. (1) shows the PFGE analysis of SmaI restriction fragments from patients harbouring S. aureus both in the nasal cavity and the leg ulcer. The figure reveals that these patients had the same type both places, thereby suggesting cross contamination between the nasal cavity and the leg ulcer. The PFGE type of the S. aureus isolates from the nasal cavity and leg ulcers of patient 4 and patient 5 was found to be identical. We cannot preclude that the strain had been transmitted from one patient to the other at the hospital premises. The result of the PFGE analysis is shown in Fig. (1). None of the S. aureus strains isolated from the chronic ulcers or the nasal cavity were found to be methicillin-resistant (MRSA). The strains isolated from the nasal cavity and the leg ulcers had identical resistance patterns. All isolates were sensitive to erythromycin, gentamicin, vancomycin and rifampicin and resistant to penicillin, mecillinam and polymyxin. Mecillinam and polymyxin are in general not considered to be functional against Gram positive bacterae. In one case the isolates from the nasal cavity and leg ulcer from the same patient were resistant to fucidin, while the remaining isolates were sensitive. These results are in accordance with the resistance profiles of 271 S. aureus isolates inhabiting chronic leg ulcer, which we also investigated (see Table 1). In this study we did not find any methicillin resistant S. aureus (MRSA). While MRSA is an increasing problem globally, the prevalence of MRSA in Denmark is quite low; in the period of 2005-2009 all departments of clinical microbiology in Denmark reported on S. aureus bacteraemia cases 6912 times; only 1.3 % exhibited resistance to methicillin [9].

Fig. (1).

PFGE of SmaI restriction fragments of S. aureus isolates. First lane for each patient is the isolate from the nasal cavity, second lane is from the leg ulcer.

Bacterial species isolated from chronic ulcers were not found to be present in the nasal cavity except for the S. aureus strains and in one case; K. oxytoca. This indicates that the ulcer microbiota in general does not originate from the nasal cavity of the patients, with the exception of S. aureus. However, it is not possible to rule out the possibility that the nasal cavity might have been an intermediate reservoir at some time point for other bacterial species than S. aureus.

S. aureus was detected in the nasal cavity of 38% of the patients, moreover S. aureus were found in 81 % of the leg ulcers identified using swab collections. We have recently shown that it is sufficient to use swab sampling to identify the bacterial species present in chronic wounds, thus avoiding complications associated with biopsy sampling [10]. The patients had the same S. aureus PFGE type in leg ulcers and nasal cavities, which indicates that cross-contamination between the ulcers and the nasal cavity occurs. Previous studies have shown that S. aureus originating in the nasal cavity may contaminate e.g. dialysis access sites [5,6]. Our study suggests that the source of contamination of leg ulcers may be the patients’ anterior nares and further implicates that removal of infecting S. aureus from the leg ulcer may be very difficult if the reservoir (the nasal cavity) remains contaminated.

CONFLICT OF INTEREST

The authors confirm that this article content has no conflicts of interest.

ACKNOWLEDGEMENTS

The study was partly financed by the Danish Research Agency under the SUE-programme (No. 9901187). Mette E. Skindersoe was supported by the Danish Centre for Antibiotic Research and Development (DanCARD, No. 09-067075) ﬁnanced by the Danish Council for Strategic Research.

About the Editor

Biography of Irina V. Kiseleva

Dr. Kiseleva obtained her MS in Microbiology from St Petersburg (SPb) State University, RF, PhD in Virology from Institute of Influenza, SPb, RF and DSci in Virology in Institute of Experimental Medicine (IEM), SPb, RF. She holds a position of Section Chief in IEM. She is also a Professor of SPb University, RF. She published over 280 publications including 40 RF patents. Currently she is the Editor-in-Chief of TOMICROJ, published by Bentham Science Publishers.

Department of Virology, Institute of Experimental Medicine, St. Petersburg, Russia

Quick Links

Indexing Agencies

Press Release

Three more Bentham Science Journals indexed in The Emerging Sources Citation Index (ESCI) by Thomson Reuters

News release date: June 6, 2017

Description:

Thomson Reuters has selected the following Journals published by Bentham Science Publishers for coverage in The Emerging Sources Citation Index (ESCI). ESCI is a new index launched by Thomson Reuters, extending the universe of publications in Web of Science to include high-quality, peer-reviewed publications of regional importance and in emerging scientific fields.

The Emerging Sources Citation Index (ESCI) is a new index launched by Thomson Reuters, extending the universe of publications in Web of Science to include high-quality, peer-reviewed publications of regional importance and in emerging scientific fields.

Adolescent Psychiatry publishes original research, critical reviews of topics relevant to practitioners, clinical observations with analysis and discussion, analysis of philosophical, ethical or social aspects of the fields of psychiatry and mental health, case reports with discussions, letters, and position papers.

Clarivate Analytics (formerly Thomson Reuters Intellectual Property & Science business) has selected the Bentham Science journal Current Molecular Pharmacology for coverage in the Science Citation Index (SCI). The Science Citation Index (SCI) is a citation index originally produced by the Institute for Scientific Information (ISI) and is made available online through different platforms, such as the Web of Science and SciSearch.

Current Molecular Pharmacology publishes the latest developments in cellular and molecular pharmacology with a major emphasis on the mechanism of action of novel drugs under development, innovative pharmacological technologies, cell signaling, transduction pathway analysis, genomics, proteomics, and metabonomics applications to drug action.

Clarivate Analytics (formerly Thomson Reuters Intellectual Property & Science business) has selected the Bentham Science journal Current Psychiatry Reviews for coverage in The Emerging Sources Citation Index (ESCI). ESCI is a new index, extending the universe of publications in Web of Science to include high-quality, peer-reviewed publications of importance in emerging scientific fields.

Current Psychiatry Reviews publishes frontier review articles and guest edited issues dedicated to clinical research on all the latest advances on clinical psychiatry and its related areas e.g. pharmacology, epidemiology, clinical care and therapy. The journal is essential reading for all clinicians, psychiatrists and researchers in psychiatry.

MEDLINE indexes Pharmaceutical Nanotechnology

News release date: March 10, 2017

Description:

Pharmaceutical Nanotechnology, an important journal published by Bentham Science, is accepted to be included in MEDLINE. MEDLINE is the U.S. National Library of Medicine® (NLM) premier bibliographic database that contains more than 23 million references to journal articles in life sciences with a concentration on biomedicine. A distinctive feature of MEDLINE is that the records are indexed with NLM Medical Subject Headings (MeSH®). For more information, view: https://www.nlm.nih.gov/pubs/factsheets/medline.html/

Pharmaceutical Nanotechnology publishes original manuscripts, reviews, thematic issues, rapid technical notes and commentaries that provide insights into the synthesis, characterization and pharmaceutical (or diagnostic) application of materials at the nanoscale.

Bentham Science among Top 14 Publishers indexed in Scopus

News release date: February 08, 2017

Description:

Scopus recently released information about the published content hosted by the service. According to the information presented, Bentham Science is among the top 14 publishers which have their publications indexed in Scopus.

Bentham Science will continue to expand on its product portfolio in line with its mission to facilitate the publication of latest research around the globe. We are also committed to increasing the exposure of researchers who publish their work with us.

About Scopus

Scopus is the largest abstract and citation database of peer-reviewed literature: scientific journals, books and conference proceedings. Delivering a comprehensive overview of the world's research output in the fields of science, technology, medicine, social sciences, and arts and humanities, Scopus features smart tools to track, analyze and visualize research.

Bentham Science Publishers is a major publisher of over 100 peer reviewed journals and 600 eBooks. Some of the notable Bentham Science journals that have received ISI Impact factor (IF) rankings are Current Neuropharmacology (IF 3.75) Current Cancer Drug Targets (IF 3.71), Recent Patents on Anti-Cancer Drug Discovery, (IF 3.53), Current Medicinal Chemistry (IF 3.46) among other titles.

Testimonials

"Open access will revolutionize 21st century knowledge work and accelerate the diffusion of ideas and evidence that support just in time learning and the evolution of thinking in a number of disciplines."

. —Daniel Pesut. (Indiana University School of Nursing, USA).

"It is important that students and researchers from all over the world can have easy access to relevant, high-standard and timely scientific information. This is exactly what Open Access Journals provide and this is the reason why I support this endeavor."

"Publishing research articles is the key for future scientific progress. Open Access publishing is therefore of utmost importance for wider dissemination of information, and will help serving the best interest of the scientific community."

. —Patrice Talaga. (UCB S.A., Belgium).

"Open access journals are a novel concept in the medical literature. They offer accessible information to a wide variety of individuals, including physicians, medical students, clinical investigators, and the general public. They are an outstanding source of medical and scientific information."

. —Jeffrey M. Weinberg. (St. Luke's-Roosevelt Hospital Center, USA).

"Open access journals are extremely useful for graduate students, investigators and all other interested persons to read important scientific articles and subscribe scientific journals. Indeed, the research articles span a wide range of area and of high quality. This is specially a must for researchers belonging to institutions with limited library facility and funding to subscribe scientific journals."

. —Debomoy K. Lahiri. (Indiana University School of Medicine, USA).

"Open access journals represent a major break-through in publishing. They provide easy access to the latest research on a wide variety of issues. Relevant and timely articles are made available in a fraction of the time taken by more conventional publishers. Articles are of uniformly high quality and written by the world's leading authorities."

. —Robert Looney. (Naval Postgraduate School, USA).

"Open access journals have transformed the way scientific data is published and disseminated: particularly, whilst ensuring a high quality standard and transparency in the editorial process, they have increased the access to the scientific literature by those researchers that have limited library support or that are working on small budgets."

. —Richard Reithinger. (Westat, USA).

"Not only do open access journals greatly improve the access to high quality information for scientists in the developing world, it also provides extra exposure for our papers."

. —J. Ferwerda. (University of Oxford, UK).

"Open Access 'Chemistry' Journals allow the dissemination of knowledge at your finger tips without paying for the scientific content."

. —Sean L. Kitson. (Almac Sciences, Northern Ireland).

"In principle, all scientific journals should have open access, as should be science itself. Open access journals are very helpful for students, researchers and the general public including people from institutions which do not have library or cannot afford to subscribe scientific journals. The articles are high standard and cover a wide area."

. —Hubert Wolterbeek. (Delft University of Technology, The Netherlands).

"The widest possible diffusion of information is critical for the advancement of science. In this perspective, open access journals are instrumental in fostering researches and achievements."

. —Alessandro Laviano. (Sapienza - University of Rome, Italy).

"Open access journals are very useful for all scientists as they can have quick information in the different fields of science."

. —Philippe Hernigou. (Paris University, France).

"There are many scientists who can not afford the rather expensive subscriptions to scientific journals. Open access journals offer a good alternative for free access to good quality scientific information."

"Open access journals have become a fundamental tool for students, researchers, patients and the general public. Many people from institutions which do not have library or cannot afford to subscribe scientific journals benefit of them on a daily basis. The articles are among the best and cover most scientific areas."

. —M. Bendandi. (University Clinic of Navarre, Spain).

"These journals provide researchers with a platform for rapid, open access scientific communication. The articles are of high quality and broad scope."

. —Peter Chiba. (University of Vienna, Austria).

"Open access journals are probably one of the most important contributions to promote and diffuse science worldwide."

"Open access journals make up a new and rather revolutionary way to scientific publication. This option opens several quite interesting possibilities to disseminate openly and freely new knowledge and even to facilitate interpersonal communication among scientists."

. —Eduardo A. Castro. (INIFTA, Argentina).

"Open access journals are freely available online throughout the world, for you to read, download, copy, distribute, and use. The articles published in the open access journals are high quality and cover a wide range of fields."

. —Kenji Hashimoto. (Chiba University, Japan).

"Open Access journals offer an innovative and efficient way of publication for academics and professionals in a wide range of disciplines. The papers published are of high quality after rigorous peer review and they are Indexed in: major international databases. I read Open Access journals to keep abreast of the recent development in my field of study."

. —Daniel Shek. (Chinese University of Hong Kong, Hong Kong).

"It is a modern trend for publishers to establish open access journals. Researchers, faculty members, and students will be greatly benefited by the new journals of Bentham Science Publishers Ltd. in this category."